Land vehicle fuel tanks typically include a connecting filler tube which is constructed with an open inlet which is positioned on one side of the vehicle. In earlier constructions this open inlet has been closed off from the atmosphere with a gas cap or closure of some type or style which may be optionally threaded or configured with a quarter-turn, bayonet style of connection. More recently, some of these older styles of removable gas caps have been replaced in newer vehicles from various manufacturers with a normally-closed, openable fitment or adapter. While this normally-closed, openable fitment or adapter could be considered a “cap”, the fact that it is not removed as part of the fuel filling or fuel additive process suggests the use of a different term to describe this component. Another acceptable description is to refer to this openable fitment or adapter as a “capless fitment”. This fitment is the key component of a capless gas tank system.
With this type of fitment or adapter (i.e. a capless inlet for the filler tube), there is no gas cap to be removed before adding fuel and/or fuel additives to the fuel tank of the vehicle. The normally-closed fitment or adapter has an internal closing flap construction which closes off the filler tube and which is first released and then pushed open upon insertion of the gas pump nozzle. The release mechanism may take on a variety of forms. The one common aspect is the need to be released as a preliminary step to the opening of the inner closing flap. What the gas pump nozzle sees is a carefully dimensioned opening as part of the capless fitment with the normally-closed closing flap. Upstream from this normally-closed flap are a pair of release projections or “buttons”, similar to a ball detent and as the gas pump nozzle pushes these buttons radially outwardly, the internal mechanism of the capless fitment allows the normally-closed closing flap to open. The use of ball detent release projections is merely one style of a suitable release mechanism.
The typical construction and arrangement of a gas pump nozzle includes a long spout, often with a slight bend, whose open end size and shape are suitable in order to engage and push the release buttons found in the center bore of a capless fitment according to the exemplary embodiment. As indicated, pushing these buttons radially outwardly results in the normally-closed closing flap now being capable of being opened by continued advancement of the end of the gas pump nozzle. This then allows fuel to be added to the fuel tank of the vehicle. In the case of electing to add a fuel additive into the fuel tank of the vehicle, a similar spout or nozzle structure needs to be provided so that the buttons (or other release mechanism features) of the capless fitment can be engaged and then released and with continued advancement of the spout or nozzle, the normally-closed closing flap is opened. Capless gas tank systems of the type generally described above have been selected for use on various models of Ford, Cadillac, GMC and Volkswagen automobiles, as but some examples.
Besides the periodic additions of fuel, the vehicle operator may decide to also use one or more of the fuel additives which are currently available on the market. The types of fuel additives being discussed herein are typically marketed in a metal container or can which includes a plastic neck insert which is externally threaded and sealed closed first by a tear-out diaphragm and then by a threaded cap. In order to dispense the fuel additive from the container or can, the threaded cap must first be removed and thereafter the tear-out diaphragm is pulled free so as to open the can. In order to actually dispense the fuel additive, the can needs to be tilted or inverted and therein lies the issue with regard to possible spillage. The relatively short axial height of the extending portion of the neck insert is not suitable for opening a capless fitment provided as part of a capless gas tank system.
Even if the vehicle which is to receive the fuel additive includes a gas tank system with a removable cap, it is still difficult to invert and insert the extended portion of the neck insert into the inlet opening of the filler tube, without some spillage either on the vehicle or on the ground. This maneuver of inverting and inserting is even more challenging when the inlet opening is recessed inwardly from the outer surface of the side panel of the vehicle. The likelihood of spills has prompted some manufacturers of these types of fuel additives to include some type of elongated, tubular spout or funnel for attachment to the threaded portion of the plastic neck insert after the threaded closing cap has been removed and after any tear-out diaphragm has been pulled free. When a spout or funnel of the type described is included with the fuel additive, it is typically secured in some fashion directly to the container, often by an extension member which is secured around an upper portion of the container thereby allowing the spout or funnel to extend axially down the outer sidewall of the container.
In terms of design constraints, materials, fabrication costs, ease of manufacture and reliability, there are several important considerations relative to what constitutes a suitable spout or funnel for attachment to the neck insert or for attachment to the neck of the container if a neck insert is not used. A first consideration is the size of the connection end of the spout or funnel which preferably threads onto the threaded end of the neck insert or onto the threaded end of the container neck finish. Another consideration is the desired axial length of the funnel. A still further consideration is the diameter size of the inserting end of the funnel.
From a fabrication time and cost perspective, injection-molding of the funnel is preferred over a blow-molding process. However, the size requirement for the inserting end of the funnel, in order to be able to properly engage the release mechanism such as the release buttons of the capless fitment for opening the normally-closed closing flap, requires a generally cylindrical form for the tubular body of the funnel as it extends between the connection end and the inserting end. The molding of a generally cylindrical form, focusing now on the hollow interior, which needs to have at least a four to six inch length, is best accomplished by blow-molding. However, blow-molding as compared to injection-molding is a slower process and is a more expensive process. Therefore, in order to retain the advantages of injection-molding, current spouts or funnels have a tapered hollow interior and thus do not have the desired dimensions for use with capless gas tank systems.
A tapered hollow interior is important for core removal, an aspect of injection molding tubular forms. The degree of taper can be relatively minor, such as 1-2 degrees. Core removal can be accomplished from either end of the tubular form, or can be accomplished from each end. Even though the hollow interior may have a modified form depending on the selected manner of core removal, there is still a tapered form as part of the interior of the tubular body for the requisite core removal when injection molding. In order to obtain the desired outside diameter for the inserting end, according to the present invention, there may be resulting variations in the wall thickness of the tubular body and this wall thickness may not be uniform throughout. See FIGS. 17-21.
As used herein, terms such as “fuel” and “gas” may be used interchangeably, without trying to identify or denote any specific technical difference between these two terms. As such, either term is acceptable and the term selected is based on what is believed to be the preferred choice based on actual use, such as “fuel tank” and “gas cap”. Further, as used herein, the term “additive” broadly includes automotive fluids such as fuel conditioners, supplements, cleaners, etc. It is also to be noted that the funnel construction disclosed herein is suitable for dispensing any flowable product from one source or container to another receptacle or reservoir.